NEW FUEL CYCLE STRATEGIES FOR VVER-440

Gagarinskiy А.А., Ivanova E.G., Lizorkin M.P., Proselkov V.N., NRC “Kurchatov Institute”, Moscow, Russia

24th Symposium of AER on VVER Reactor Physics and Reactor Safety (2014, Sochi, Russia)
Fuel management issues

Abstract

NEW FUEL CYCLE STRATEGIES FOR VVER-440
Gagarinski A.A., Ivanova E.G., Lizorkin M.P., Proselkov V.N. NRC “Kurchatov Institute”, Moscow, Russia
ABSTRACT
Wide implementation of second-generation VVER-440 (V-213) reactors is characteristic for the contemporary phase of development of medium water-water reactors, which are in operation at NPPs such as Loviisa (Finland), Paks (Hungary), Dukovany (Czech Republic), Mochovce and Bohunice (Slovakia), Rovno (Ukraine), Kola (Russia) and Metsamor (Armenia). Two new VVER-440 units (3 and 4) will be launched at the Mochovce NPP in 20152016. So the improvement of fuel and fuel cycles for VVER-440 is an important task today.
Contemporary fuel cycle strategies for VVER-440 are different compared to those used in 20002010.
The basic features of the contemporary VVER-440 fueling strategy are:

• capability to operate at an uprated thermal power level with fuel load lifetime of at least 340 effective days;
• fuel burnup limited by 68 MWday/kgU (average per fuel rod);
• optimized fuel enrichment profile with respective reduction of the initial fuel enrichment;
• lower conservatism of fuel cycle validation. To meet these tasks, it is necessary to:
• increase the share of fuel to be replaced in the course of refueling, in order to allow an uprated thermal power operation;
• shift from a six-year fuel cycle to a four- or five-year one.
  This paper presents relevant results for fuel cycles with second-generation assemblies, which were developed for Slovak NPP units to enable their operation at an uprated power level of 109%.
  These results were obtained for VVER-440 fuel cycles based on RK2+ assemblies with higher U content and RK3 assemblies, assuming the reactor to operate at uprated thermal power levels of 107% (1471 MW), 109% (1498 MW) and 112% (1540 MW).
  Advantages of the fuel cycle based on RK2+ assemblies with U-235 enrichment higher than 5% are also analyzed.

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